Cindy,
Can you post a picture of one, to make sure they are zoa eating nudi's? I am suprised to hear that FWE did not touch them. It is my understanding that FWE is the only thing that will kill them. I had to use FWE at 5x or so time's it's normal dose, which ended up destroying my tank a little over a year ago. If they are zoa eating nudi's, they are nasty, and bad news. I agree with Daniel. Pull out all of your zoa's, and put them in another tank. Leave them out of your DT for at least 6-8 weeks after you are sure they are all dead. This way you can treat the smaller tank, while all of the nudi's in your DT die off (they won't have any food to eat).
The eggs will be white, and look like a spiral, usually on the side of a zoa, but can also be on a rock, or possible a different coral. Anyone who has received a coral from you, could have potentially received an egg or a baby.
I would also add a yellow coris to both tanks, then sell the other when you are done with your treatment. They will eat them, but not a ton of them, because the nudi's are toxic, and you probably also have a ton of pods in your tank to keep the wrasse on a diversified diet.
You'll also notice their colors will change. This is because they will take on the color from the zoa they've been munching on.
Good luck!!